上顎側方拡大装置のラット顎下腺および舌下腺に及ぼす影響

抄録

The effects of the application of an orthodontic apparatus for the maxillary lateral expansion on rat submandibular and sublingual glands were examined by the biochemical, histochemical, immunohistochemical, radioimmunological and electrophoretic methods for 1 month. In the sublingual glands the enlargement was observed on the 3rd day, whereas in the submandibular glands it was found at 1 week after the orthodontic treatment. Significant elevation of the nucleic acid levels in both salivary glands occurred in accordance with this enlargement. These results suggest that hypertrophy and hyperplasia occurred in both glands. These changes were completely restrained by phenoxybenzamine (Phenox) in both glands, but in sublingual glands atropine also restrained the enlargement. However, 6-hydroxydopamine (6-OHD) did not reduce wet weights of both glands. An abnormal protein which appeared after the isoproterenol chronic treatment was also found in both saliva and submandibular glands at later stages after the orthodontic treatment. The level of this abnormal protein, identified by the gel precipitation test and different electrophoreses, increased by both 6-OHD and Phenox. In contrast, two protease activities in the convoluted granular tubule cell in the submandibular gland showed clear reduction week by week after the orthodontic treatment. The level of substance P in both glands significantly increased at early stages after the orthodontic treatment but thereafter it returned to the control level. Substance P did not elevate the levels of cAMP and cGMP, and the secretory responses of substance P in the submandibular glands were not significantly reduced with any autonomic blocker and morphine. However, noradrenaline potentiated the actions of substance P in the submandibular glands. It is suggested that both submandibular and sublingual glands of rats are strongly affectd by this orthodontic treatment via both autonomic and somatic nervous systems. However, these effects completely disappeared after removal of this orthodontic apparatus.